Screen randomly messes up

Please answer the questions in video to yourself and then give a more detailed description, as there are many reasons depending on what exactly is happening. TV Repair Help for Vertical Horizontal Lines on Your TV Screen...

The Sony diagnostic routine for 4 blinks indicates it to be a vertical deflection problem.

Did you see a solid horizontal line in the center of the screen prior to it going out? If so, that is a tell tale sign for vertical problems.

basic sony reset below

The STANDBY light will flash if the television detects an issue within the television. Some of these issues can be resolved simply by following the steps below to reset the television.

1. Turn off the television. IMPORTANT: For a projection television that uses an internal lamp, wait 5 minutes after turning off the television to allow the lamp to cool before continuing with the following steps.
   
2. Unplug the television power cord from the electrical outlet.
3. Let the television remain without power for 60 seconds.
4. Plug the power cord back into the electrical outlet. NOTE: If the television is plugged into a power strip or surge protector, remove it from the power strip or surge protector and plug it directly into the wall outlet. If the issue is resolved, the problem is with the power strip or surge protector and not the television.
   
5. Turn on the television.

If the issue is still unresolved after following all of the troubleshooting steps, service may be required. Please note the number of times the STANDBY light flashes and relay that information to the service center

Sound like your Y-Sustain board has one foot in the grave. The Y upper buffer and Y lower buffer boards go when the Y Sus Goes too...

Four blinks - No vertical Deflection (V STOP), Screen goes to a single horizontal line then the video signal muted. Check IC1509, Q1505

Try to hold the slide key for 15 sec. It will reboot your kindle. If black patch is not gone even after that, It's a hw issue. Screen might require to be changed. If it's in warranty Amazon will do it free. That's what i have heard.

Display section bad.

This is a vertical problem. It may have a bad solder joint or it has a vertical IC or surrounding compoenents heating up and going bad, Try not to have the horizonal line on for to long, it can burn the screen if left on very long. If you have some electronic experience you could get some freeze spray and wait for the set to mess up and spray the freeze around the vertical section and locate the part that is heating up. Be careful because there is HIGH VOLTAGE is this area. Hope this is helpful.

REPLACED LCD PANEL
Manufacturer Sharp Part Number RF-R1LK420D3LF2 Description 42" WIDE LCD PNL -

This should be a quick fix. Try resoldering the vertical IC. This is a small flat IC attached to a heat sink with about 11 pins. It should be marked LA7837 or something similar. That should resolve the problem.

Keep us posted.
Dan

The most common problem (I have fixed lots) is the Vertical amplifier has developed a loose connection. It probably just needs resoldering. As things expand it makes and looses connection you picture goes in and out. The vertical chip is a large black chip that gets hot, over time it degrades the solder until a connection is damaged. Most newer sets have a protection circuit that senses the lack of height, and shuts down the picture tube to save it. When the picture dropped to a line on older TVs and left that way too long it would burn a line into the face of the picture tube. You then had to have the picture tube replaced along with the vertical amp. it's kinda like a screensaver for your TV.